Periodic Reporting for period 2 - FOXES (Fully Oxide-based Zero-Emission and Portable Energy Supply) Reporting period: 2022-04-01 to 2023-09-30 Summary of the context and overall objectives of the project FOXES aims at establishing a new, eco-friendly paradigm for powering wireless devices of the Internet of Things (IoT). FOXES is an acronym for “Fully Oxide-based Zero-Emission and Portable Energy Supply”.IoT is the core technology for future-defining concepts like autonomous driving and automated factories, and enables CO2 emissions reduction through improved efficiency of machines and industrial processes. In order to fully realize the IoT potential, interconnected devices need to be fully wireless and energy-autonomous. The goal of FOXES is to develop a Power Cube – a compact 2 x 2 cm2 device that combines a high-efficiency solar cell with a high-energy density capacitor and an energy management circuit able to ensure full energy-autonomous operation of an IoT sensor node. FOXES Power Cube will be lightweight, free from toxic or rare elements, and will have no negative environmental impact for its end-of-life.FOXES realizes a radically new paradigm for providing power generation for applications requiring energy autonomy ranging from sensor networks and IoT devices to mobile use in the transport sector, industrial settings and emergency situations. Moreover, we will define a roadmap for scaling up the FOXES technology. Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far MCL:The composition of the BaZrxTi1-xO3 (BZT) films was further optimized since the last reporting period and tests with metal oxide top and bottom electrodes conducted. The optimum energy storage performance has been achieved in the range 10%-20% of Zr content, optimal value being 15% of Zr.and with > 10 J/cm3 recoverable energy density can be reached at high electric fields in aqueous-based BaZrxTi1-xO3 thin films amount of energy of 0.12 mJ can be stored in the TFC at the input voltage of the FOXES Power Cube (12 V). To reach the goal of 0.6 mJ stored energy in the FOXES TFC, multiple 2x2 cm2 capacitors will be connected.AMO:AMO developed a compatible low-temperature 2D dry transfer method for graphene applicable to all types of perovskites, including both all-inorganic and hybrid organic-inorganic perovskites. Through experimental outcomes, a method operating at low temperatures (~50°C) was established to prevent perovskite recrystallization. This developed process facilitated the dry transfer of various 2D materials (such as Gr, hBN, MoS2) onto different perovskite dimensions - 3D, 2D, and 0D.BUW:We developed deposition protocols for three lead-free perovskite materials with band gaps aiming for tandem applications: low band gap perovskite with ~1.4 eV FASnI3, and all-inorganic perovskite CsSnBr3 with ~1.86 eV. First lead-free perovskite solar cells yield power conversion efficiencies of ~5 %. We developed an ultra-thin ALD grown InOx interconnecting layer that can be applied for lossless transfer charges from one sub-cell into the other. We have successfully set a new world record for these kinds of devices (published: Nature volume 604, pp. 280-286 (2022).The FASnI3 PSCs were unable to meet the requirements of stability, thus we used organic non-fullerene acceptor (NFA) solar cells instead. The NFA solar cells meet the stability target of 1000 h and achieve an efficiency of > 18 % under 400 lux. A mini-module connecting 10 organic NFA OSCs in serial on a 2x2 cm2 substrate has been realized, which generates a power of about 26 µW under 400 lux illumination and thus fulfill the project specifications of 6 µW/cm.UB:A first generation of sensors based on illuminated metal oxides have been produced to tackle NO2 and O3 gases. Other market-relevant gases will be addressed based on a colorimetric readout principle; with chips developed in this second period. Both the analog measurement and control circuits and the digital management units have been implemented in a full custom IC (ASIC). All the IoT Bundle is functional with discrete components, while the fully integrated version has been sent out for production. Two wireless communication protocols - Ble for low-range/low-power, and LoRa for long-range/high-power - are available and functional. Moreover, ultra-low power wake-up timers, supercap charging features are also developed and ready.UNOVA:UNOVA developed of two devices models, one based on artificial neural networks (ANNs), other physical-based, with improved accuracy. Multiple strategies for multilevel interconnects have been explored in parallel, including ink-jet printed metals and oxides (sub-150 micron), physical vapor deposition, direct laser writing and substrate conformable imprint lithography. Implementation of ALD multilayer dielectrics (Ta2O5+Al2O3) in oxide thin film transistors TFTs resulted in a mobility of 15 cm2/Vs, and Von~0 V. The development of self-aligned oxide TFT process enables channel lengths of 2 µm and channel length shortening effect (ΔL) of 160 nm, setting a very small L as the effective limit for miniaturization of the current fabrication process. A EMC v1 has been designed and simulated using PragmatIC PDK, with active area of 8.7x12.4 mm² and a device count of 1324 TFTs, 2913 capacitors and 264 resistors. Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far) MCL:Novel aqueous chemical solution depositions of RuO2, SrRuO3, and BZT have been developed. All parameters, such as solvents, additives, spin-coating parameters, concentrations, temperature process, gas atmosphere, and post-annealing have been optimized to yield high quality thin films. Since our spin-coating process is cheap, can be automated using robots and employs only non-toxic chemicals. it could be very interesting for industrial processes. Moreover, the process can be upscaled even to 300 mm wafer size.AMO:A graphene sheet has been directly transferred onto all types of perovskites, including both all-inorganic and hybrid organic-inorganic perovskites, for the first time. The developed dry transfer method enables the leveraging of the benefits of 2D materials in various perovskite optoelectronic devices, such as solar cells, light-emitting and laser diodes, or photodetectors, , serving as a diffusion barrier between the perovskite and electrodes or as an encapsulation layer to increase the stability of these devices.BUW:BUW developed a novel ultra-thin ALD grown InOx interconnecting layer that can be applied for lossless transfer charges from one sub-cell into the other. For the first time gas quenching and thermal hot pressing was successfully applied to lead- and tin-free perovskite materials, yielding unprecedentedly smooth layers. Also, for the first time BUW was able to show one step processed FASnI3 perovskite layer on top of a self-assembled monolayer (MeO-2PACz) HTL by using a thin PEAI interlayer.UB:Ultra-low power features in different chip design domains are achieved (wake up timers, current DACs, resistance measurement oscillation circuits, etc.). Also, sensor chips display record power consumption values (both illuminated gas sensors and colorimetric), as well as unique sensing capabilities (e.g. formadehyde).UNOVA:Sub-50 nm linewidth lines patterned on flexible substrates, printed ZTO TFTs operating below 2 V, and methacrylate-based ZTO inks with area-selective transfer to a substrate using UV, has been successfully achieved. These processes are being combined to obtain nm-scale oxide TFTs using resist-free direct SCIL. Energy Management Circuit fully designed using flexible oxide TFTs, never demonstrated before with such technology. Schematic of possible applications of FOXES technology
